Imaging apparatus and imaging sensor

ABSTRACT

The pixel region includes a first phase difference pixel group including a plurality of the phase difference pixels of which the first side of the photoelectric conversion element is blocked by the light blocking layer in a first side region of the first side, and a second phase difference pixel group including a plurality of the phase difference pixels of which the second side of the photoelectric conversion element is blocked by the light blocking layer. The first phase difference pixel group includes a first A pixel and a first B pixel in which a light blocking area of the photoelectric conversion element using the light blocking layer is smaller than that of the first A pixel. The controller performs addition readout processing in which at least one of a pixel signal of the first A pixel or a pixel signal of the first B pixel is weighted in accordance with optical characteristics of the imaging lens.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of and claims prioritybenefit of U.S. application Ser. No. 17/892,127, filed Aug. 22, 2022,the disclosure of which is incorporated herein by reference in itsentirety. Further, U.S. application Ser. No. 17/892,127 is acontinuation application of International Application No.PCT/JP2021/000900, filed Jan. 13, 2021, the disclosure of which isincorporated herein by reference in its entirety. Further, thisapplication claims priority from Japanese Patent Application No.2020-034192 filed on Feb. 28, 2020, the disclosure of which isincorporated herein by reference in its entirety.

BACKGROUND 1. Technical Field

The technique of the present disclosure relates to an imaging apparatusand an imaging sensor.

2. Description of the Related Art

As the automatic focus detection method of the imaging apparatus, thereare a contrast detection method and a phase difference detection method.In the phase difference detection method, the luminous flux that haspassed through the exit pupil of the imaging lens is divided into twoparts, and the divided luminous flux is received by a pair of phasedifference pixels (also referred to as focus detection pixels).

JP2011-101325A discloses an imaging apparatus having a plurality oftypes of phase difference pixels having different light receivingdistributions in addition to the plurality of imaging pixels. Theimaging apparatus described in JP2011-101325A is able to select onethinning-out readout mode from a plurality of thinning-out readout modeshaving different thinning phases in a case where a plurality of pixelsare thinned out and read out. For the plurality of types of phasedifference pixels, only the signal of one type of phase difference pixelis read out in accordance with the selected thinning-out readout mode.

SUMMARY

One embodiment according to the technique of the present disclosureprovides an imaging apparatus and an imaging sensor capable ofperforming focusing control using a pixel signal of an appropriate phasedifference pixel according to optical characteristics of the imaginglens.

In order to achieve the above object, according to an aspect of thepresent disclosure, there is provided an imaging apparatus comprising: apixel region in which a plurality of pixels are arranged and into whichlight is incident through an imaging lens; and a controller thatcontrols readout of a pixel signal from the pixel region. In the pixelregion, phase difference pixels, each of which includes a photoelectricconversion element, and a light blocking layer, which blocks a part oflight incident on the photoelectric conversion element, are arrangedalong a first direction. In a case where one side in the first directionis set as a first side and the other side is set as a second side, thepixel region includes a first phase difference pixel group including aplurality of the phase difference pixels of which the first side of thephotoelectric conversion element is blocked by the light blocking layerin a first side region of the first side, and a second phase differencepixel group including a plurality of the phase difference pixels ofwhich the second side of the photoelectric conversion element is blockedby the light blocking layer, and the first phase difference pixel groupincludes a first A pixel and a first B pixel in which a light blockingarea of the photoelectric conversion element using the light blockinglayer is smaller than that of the first A pixel. The controller performsaddition readout processing in which at least one of a pixel signal ofthe first A pixel or a pixel signal of the first B pixel is weighted inaccordance with optical characteristics of the imaging lens.

It is preferable that the second phase difference pixel group includes asecond A pixel and a second B pixel in which a light blocking area ofthe photoelectric conversion element using the light blocking layer islarger than that of the second A pixel, and the controller performsaddition readout processing in which either one of a set of the first Apixel and the second A pixel or a set of the first B pixel and thesecond B pixel is weighted in accordance with the opticalcharacteristics of the imaging lens.

It is preferable that the pixel region has an A pixel line that includesthe first A pixel and has a plurality of pixels arranged in the firstdirection, and a B pixel line that includes the first B pixel and has aplurality of pixels arranged in the first direction. It is preferablethat the A pixel line and the B pixel line are arranged in a seconddirection intersecting with the first direction, and the controllerperforms addition readout processing in which either one of the A pixelline or the B pixel line is weighted in accordance with the opticalcharacteristics of the imaging lens.

It is preferable that the first phase difference pixel group is alsoincluded in a central region located at a center of the pixel regionwith respect to the first direction, in the A pixel line, a lightblocking area of the first A pixel which is included in the first sideregion is larger than a light blocking area of the first A pixel whichis included in the central region, and in the B pixel line, a lightblocking area of the first B pixel which is included in the first sideregion is equal to a light blocking area of the first B pixel which isincluded in the central region.

It is preferable that the light blocking area of a plurality of thefirst A pixels which are included in the A pixel line is smaller at aposition closer to the central region than the first side region.

It is preferable that the A pixel line and the B pixel line are adjacentto each other in the second direction.

It is preferable that in the pixel region, the phase difference pixelswhich are included in the first phase difference pixel group are formedin a second side region on the second side, and in the A pixel line, alight blocking area of the first A pixel which is included in the secondside region is smaller than a light blocking area of the first A pixelwhich is included in the first side region.

It is preferable that the optical characteristics are an incidence angleof the light with respect to the pixel region, a focal length of theimaging lens, or a zoom magnification of the imaging lens.

It is preferable that the focal length of the imaging lens can bechanged, and the controller changes the weight in a case where the focallength is changed and the change is stopped.

It is preferable that the controller acquires the opticalcharacteristics from the imaging lens and determines the weight on thebasis of the acquired optical characteristics.

It is preferable that in a case where the optical characteristics areunlikely to be acquired from the imaging lens, the controller determinesthe weight on the basis of an exposure amount of the light to the firstA pixel and the first B pixel.

It is preferable that the second phase difference pixel group includesthe second A pixel and the second B pixel having the same light blockingarea as the first B pixel, and in a case where the opticalcharacteristics of the imaging lens are unlikely to be acquired, thecontroller sets the weight for the set of the first A pixel and thesecond A pixel to zero.

It is preferable that the pixel region has a gate line that extends inthe first direction and selects the photoelectric conversion elementwhich reads out the pixel signal, and a signal line that extends in asecond direction intersecting with the first direction and outputs apixel signal from the photoelectric conversion element.

It is preferable that the addition readout processing includesthinning-out readout processing in which the weight is set to zero sothat a pixel signal having a weight of zero is thinned out and a pixelsignal whose weighting is not zero is read out.

According to an aspect of the present disclosure, there is provided animaging sensor comprising: a pixel region in which a plurality of pixelsare arranged. In the pixel region, phase difference pixels, each ofwhich includes a photoelectric conversion element, and a light blockinglayer, which blocks a part of light incident on the photoelectricconversion element, are arranged along a first direction, in a casewhere one side in the first direction is set as a first side and theother side is set as a second side, the pixel region includes a firstphase difference pixel group including a plurality of the phasedifference pixels of which the first side of the photoelectricconversion element is blocked by the light blocking layer in a firstside region of the first side, and a second phase difference pixel groupincluding a plurality of the phase difference pixels of which the secondside of the photoelectric conversion element is blocked by the lightblocking layer, and the first phase difference pixel group includes afirst A pixel and a first B pixel in which a light blocking area of thephotoelectric conversion element using the light blocking layer issmaller than that of the first A pixel, and the second phase differencepixel group includes a second A pixel and a second B pixel in which alight blocking area of the photoelectric conversion element using thelight blocking layer is larger than that of the second A pixel.

It is preferable that the pixel region includes an imaging pixel havinga color filter and the photoelectric conversion element, the first Apixel and the second A pixel are arranged such that three or less of theimaging pixels are interposed therebetween, and the first B pixel andthe second B pixel are arranged such that three or less of the imagingpixels are interposed therebetween.

It is preferable that the pixel region has an A pixel line that includesthe first A pixel and has a plurality of pixels arranged in the firstdirection, and a B pixel line that includes the first B pixel and has aplurality of pixels arranged in the first direction, and the A pixelline and the B pixel line are arranged in a second directionintersecting with the first direction.

It is preferable that the first phase difference pixel group and thesecond phase difference pixel group are also arranged in a second sideregion on the second side of the pixel region, in the second sideregion, a light blocking area of the first A pixel is smaller than alight blocking area of the first B pixel, and in the second side region,a light blocking area of the second A pixel is larger than a lightblocking area of the second B pixel.

It is preferable that in the first side region, the first phasedifference pixel group includes a first C pixel in which a lightblocking area of the photoelectric conversion element using the lightblocking layer is smaller than that of the first B pixel, and in thefirst side region, the second phase difference pixel group includes asecond C pixel in which a light blocking area of the photoelectricconversion element using the light blocking layer is larger than that ofthe second B pixel.

It is preferable that the pixel region has a gate line that extends inthe first direction and selects the photoelectric conversion elementwhich reads out the pixel signal, and a signal line that extends in asecond direction intersecting with the first direction and outputs apixel signal from the photoelectric conversion element.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments according to the technique of the presentdisclosure will be described in detail based on the following figures,wherein:

FIG. 1 is a schematic perspective view showing a front side of animaging apparatus,

FIG. 2 is a schematic perspective view showing a rear side of theimaging apparatus,

FIG. 3 is a schematic view showing an internal configuration of theimaging apparatus,

FIG. 4 is a diagram showing an example of lens information,

FIG. 5 is a schematic diagram showing a principal ray angle,

FIG. 6 is a diagram showing a configuration example of an imagingsensor,

FIG. 7 is a diagram showing an example of addition readout,

FIG. 8 is a diagram showing a relationship between an addition readoutmode and a weight,

FIG. 9 is a diagram showing types of pixels which are included in apixel region,

FIG. 10 is a diagram showing a configuration of imaging pixels,

FIG. 11 is a diagram showing a configuration of phase difference pixels,

FIG. 12 is a diagram showing types of phase difference pixels which areincluded in each region of the pixel region,

FIG. 13 is a diagram showing a configuration of phase difference pixelswhich are included in the A pixel line,

FIG. 14 is a diagram showing a configuration of phase difference pixelswhich are included in the B pixel line,

FIG. 15 is a diagram showing a configuration of phase difference pixelswhich are included in the C pixel line,

FIG. 16 is a diagram showing an overall configuration of phasedifference pixels which are included in the pixel region,

FIG. 17 is a flowchart showing a procedure of processing executed by themain controller,

FIG. 18 is a diagram showing a procedure for selecting an additionreadout mode on the basis of lens information,

FIG. 19 is a diagram showing a fifth addition readout mode,

FIG. 20 is a diagram showing a sixth addition readout mode,

FIG. 21 is a diagram showing a table in which peripheral principal rayangles are associated with each other,

FIG. 22 is a flowchart showing weight change processing according to afourth embodiment,

FIG. 23 is a diagram showing differences in exposure amount of phasedifference pixels caused by differences in optical characteristics, and

FIG. 24 is a flowchart showing weight determination processing accordingto a fifth embodiment.

DETAILED DESCRIPTION

An example of an embodiment relating to the technique of the presentdisclosure will be described with reference to the accompanyingdrawings.

First, the wording used in the following description will be described.

In the following description, the “CPU” is an abbreviation for “CentralProcessing Unit”. The “ROM” is an abbreviation for “Read Only Memory”.The “RAM” is an abbreviation for “Random Access Memory”. The “CMOS” isan abbreviation for “Complementary Metal Oxide Semiconductor”. The“FPGA” is an abbreviation for “Field-Programmable Gate Array”. The “PLD”is an abbreviation for “Programmable Logic Device”. The “ASIC” is anabbreviation for “Application Specific Integrated Circuit”.

In the present disclosure, as used herein, the term “parallel” refers toparallelism in the sense that, in addition to perfect parallelism,errors generally tolerated in the art of the technique of the presentdisclosure. As used herein, the term “equal” includes not only beingexactly equal, but also being substantially equal in the sense that itincludes errors that are generally tolerated in the art of the techniqueof this disclosure.

First Embodiment

As a first embodiment of the imaging apparatus, the technique of thepresent disclosure will be described by using an interchangeable lensdigital camera as an example.

As shown in FIG. 1 , the imaging apparatus 10 is a interchangeable lensdigital camera. The imaging apparatus 10 includes a body 11 and animaging lens 12 interchangeably attached to the body 11.

A camera side mount 11A is provided on a front surface 11C of the body11. The imaging lens 12 is provided with a lens side mount 12A on therear end side. By attaching the lens side mount 12A to the camera sidemount 11A, the imaging lens 12 is connected to the body 11.

In the present embodiment, the imaging lens 12 is a single focus lenshaving a fixed focal length. A plurality of types of imaging lenses 12having different focal lengths can be attached to the body 11.

The body 11 is provided with an imaging sensor 20. In the imaging sensor20, the light-receiving surface 20A is exposed from an opening of thecamera side mount 11A. In a case where the imaging lens 12 is attachedto the body 11, the luminous flux from the subject passes through theimaging lens 12 and is imaged on the light-receiving surface 20A of theimaging sensor 20. The imaging sensor 20 captures an image of theluminous flux formed on the light-receiving surface 20A and generates animaging signal.

A dial 13 and a release button 14 are provided on an upper surface ofthe body 11. The dial 13 is operated in a case of setting the operationmode or the like. The operation mode of the imaging apparatus 10includes, for example, a still image capturing mode and a motion picturecapturing mode. The release button 14 is operated in a case of startingimaging in the still image capturing mode or the motion picturecapturing mode.

As shown in FIG. 2 , a display 15 and an instruction key 16 are providedon a rear surface 11D of the body 11. The display 15 displays an imagebased on image data obtained by imaging, various menu screens, and thelike.

The instruction key 16 receives various instructions. Here, the “variousinstructions” are, for example, an instruction to display a menu screenon which various menus can be selected, an instruction to select one ora plurality of menus, an instruction to confirm the selected contents,an instruction to delete the selected contents, and various instructionssuch as autofocus mode, manual focus mode, and frame advance. Inaddition, the body 11 is provided with a power switch and the like.

FIG. 3 shows an internal configuration of the imaging apparatus 10 in astate where the imaging lens 12 is attached to the body 11. The body 11and the imaging lens 12 are electrically connected to each other bybringing the electric contact 11B provided on the camera side mount 11Ainto contact with the electric contact 12B provided on the lens sidemount 12A.

The imaging lens 12 includes an objective lens 30, a focus lens 31, arear end lens 32, and a stop 33. Each member is disposed in the order ofthe objective lens 30, the stop 33, the focus lens 31, and the rear endlens 32 from the objective side along an optical axis OP of the imaginglens 12. The objective lens 30, the focus lens 31, and the rear end lens32 constitute an imaging optical system. The type, number, andarrangement order of the lenses constituting the imaging optical systemare not limited to the example shown in FIG. 3 .

Further, the imaging lens 12 has a lens driving controller 34 and amemory 35. The lens driving controller 34 is constituted of a CPU, RAM,ROM, and the like. The lens driving controller 34 is electricallyconnected to the main controller 40 in the body 11 through the electriccontact 12B and the electric contact 11B.

The lens driving controller 34 drives the focus lens 31 and the stop 33on the basis of the control signal transmitted from the main controller40. The lens driving controller 34 controls driving of the focus lens 31on the basis of the control signal for focusing control transmitted fromthe main controller 40 in order to adjust the focusing position of theimaging lens 12. The main controller 40 performs focusing control by aphase difference method.

The stop 33 has an opening of which an opening diameter is variableabout the optical axis OP. The lens driving controller 34 controlsdriving of the stop 33 on the basis of the stop adjustment controlsignal transmitted from the main controller 40 in order to adjust thelight amount incident on the light-receiving surface 20A of the imagingsensor 20.

The memory 35 is a non-volatile memory such as a flash memory. Thememory 35 stores lens information 35A about the optical characteristicsof the imaging lens 12. The lens information 35A is information thatdiffers depending on the type of the imaging lens 12. The lensinformation 35A includes information about the incidence angle of theprincipal ray (hereinafter referred to as the principal ray angle) withrespect to the light-receiving surface 20A of the imaging sensor 20.

The body 11 includes the imaging sensor 20, the main controller 40, animage processing unit 41, an operation unit 42, and the display 15. Themain controller 40 controls operations of the imaging sensor 20, theimage processing unit 41, the operation unit 42, and the display 15. Themain controller 40 is constituted of a CPU, RAM, ROM, and the like.

The imaging sensor 20 is, for example, a CMOS type imaging sensor. Theimaging sensor 20 is disposed such that the optical axis OP isorthogonal to the light-receiving surface 20A and the optical axis OP islocated at the center of the light-receiving surface 20A. A luminousflux LF that has passed through the exit pupil EP of the imaging lens 12is incident on the light-receiving surface 20A. A plurality of pixelsthat generate pixel signals by performing photoelectric conversion areformed on the light-receiving surface 20A. The imaging sensor 20generates an imaging signal constituted of pixel signals of each pixelby photoelectrically converting the light incident on each pixel.

The image processing unit 41 generates image data in a default fileformat (for example, JPEG format) by performing various kinds of imageprocessing on the imaging signal. The display 15 displays an image onthe basis of the image data generated by the image processing unit 41.The image includes a still image, a motion picture, and a live viewimage. The live view image is an image that is displayed in real time onthe display 15 by sequentially outputting the image data, which isgenerated by the image processing unit 41, to the display 15.

The image data, which is generated by the image processing unit 41, canbe stored in an internal memory (not shown) built in the body 11 or astorage medium (memory card or the like) that can be attached to anddetached from the body 11.

The operation unit 42 includes the dial 13, the release button 14, andthe instruction key 16 (refer to FIGS. 1 and 2 ) described above. Themain controller 40 controls each unit in the body 11 and the lensdriving controller 34 in the imaging lens 12 in accordance with theoperation of the operation unit 42.

Further, in a case where the imaging lens 12 is connected to the body11, the main controller 40 acquires the lens information 35A stored inthe memory 35 through the lens driving controller 34. In the presentembodiment, the main controller 40 performs focusing control by a phasedifference method on the basis of the principal ray angle informationwhich is included in the lens information 35A.

FIG. 4 is an example of the lens information 35A which is stored in thememory 35. In the lens information 35A, a principal ray angle θ isrecorded as a numerical value representing a relationship with an imageheight H. The lens information 35A may include an upper ray angle, alower ray angle, and the like in addition to the principal ray angle θ.These information are unique to the imaging lens 12 and can be obtainedfrom the design data of the imaging optical system.

FIG. 5 is a schematic diagram showing the principal ray angle θ. Asshown in FIG. 5 , the principal ray angle θ is an angle formed by theprincipal ray PR passing through the center of the exit pupil EP and thenormal line of the light-receiving surface 20A at an image formationpoint IP. The image height H represents a distance from the optical axisOP to the image formation point IP.

The principal ray angle θ is “0” in a case where the image formationpoint IP coincides with the center of the light-receiving surface 20A(that is, in a case where H=0). The principal ray angle θ increases asthe image formation point IP moves away from the center of thelight-receiving surface 20A (that is, the image height H increases). Thereference numeral UR in FIG. 5 represents the upper ray, and thereference numeral LR represents the lower ray.

FIG. 6 shows an example of the configuration of the imaging sensor 20.The imaging sensor 20 includes a pixel region 21, a vertical scanningcircuit 22, a line memory 23, a horizontal scanning circuit 24, and anoutput amplifier 25. In the pixel region 21, a plurality of pixels 26are arranged in a two-dimensional matrix along the X direction and the Ydirection. The pixel 26 includes a photoelectric conversion element 27that converts incident light into a signal charge and stores the signalcharge. The photoelectric conversion element 27 is constituted of aphotodiode. Further, the pixel 26 includes an amplifier that converts asignal charge into a voltage signal (hereinafter, referred to as a pixelsignal), a reset switch, and the like. The pixel 26 outputs a pixelsignal S according to the light amount of incident light.

Here, the Y direction is orthogonal to the X direction. The X directionis an example of the “first direction” according to the technique of thepresent disclosure. The Y direction is an example of the “seconddirection” according to the technique of the present disclosure.

A plurality of gate lines 22A, which extend in the X direction, areconnected to the vertical scanning circuit 22. A plurality of signallines 23A, which extend in the Y direction, are connected to the linememory 23. The plurality of gate lines 22A and the plurality of signallines 23A intersect with each other in the pixel region 21. Each pixel26 is provided at a position where the gate line 22A and the signal line23A intersect with each other. Each pixel 26 is connected to the signalline 23A through a transistor 28 as a switch. The gate electrode of thetransistor 28 is connected to the gate line 22A.

The pixels 26 in the pixel region 21 are selected line by line by theselection signal given to the gate line 22A from the vertical scanningcircuit 22. In a case where the selection signal is given to the gateline 22A by the vertical scanning circuit 22, the pixel signal S isoutput from each pixel 26 connected to the gate line 22A to the signalline 23A. Hereinafter, a plurality of pixels 26 arranged in the Xdirection may be simply referred to as “row”.

The line memory 23 stores the pixel signal S output from the pixel 26for one line. The line memory 23 is constituted of a capacitor or thelike. The line memory 23 is connected to the horizontal output line 24Athrough a transistor 29 as a switch. The output amplifier 25 isconnected to the end of the horizontal output line 24A. The horizontalscanning circuit 24 sequentially outputs the pixel signals S for oneline stored in the line memory 23 to the horizontal output line 24A byperforming horizontal scanning in which the transistors 29 aresequentially selected. The pixel signal S, which is output to thehorizontal output line 24A, is output to the external image processingunit 41 as an imaging signal through the output amplifier 25.

The main controller 40 controls operations of the vertical scanningcircuit 22, the line memory 23, and the horizontal scanning circuit 24.By controlling the vertical scanning circuit 22, the main controller 40makes it possible to read out the pixel signal S by the “sequentialreadout method” or the “addition readout method”. The sequential readoutmethod is a method in which the pixel signal S is read out line by lineby sequentially selecting the gate lines 22A in the Y direction.

The addition readout method is a method in which pixel signals S for aplurality of rows are added and read out in accordance with the weightby weighting each of the plurality of gate lines 22A. The additionreadout also includes thinning out readout in which the pixel signal Sincluded in the row in which the weight is set to zero is not read out(that is, thinned out) by setting the weight for at least one gate line22A to zero.

The imaging sensor 20 may include an A/D converter in order to output adigitized imaging signal. The main controller 40 is an example of the“controller” according to the technique of the present disclosure. Inaddition to the main controller 40, the imaging sensor 20 may include acontroller for controlling the vertical scanning circuit 22, the linememory 23, and the horizontal scanning circuit 24.

FIG. 7 shows an example of addition readout. FIG. 7 shows an example inwhich the signal amount of the imaging signal is reduced to ¼ times byperforming addition readout with weights for every four rows in the Ydirection. In the present example, “¼ pixel thinning-out readout” forreading the pixel signal S from one row of the four rows will bedescribed.

As shown in FIG. 7 , the address of the gate line 22A (hereinafterreferred to as a row address) is set to 0, 1, 2, 3, . . . in this order.In the present example, the main controller 40 sets a weight of “0” or“1” to each row address. It is assumed that W0 is a weight of the rowhaving the row address 4n, W1 is a weight of the row having the rowaddress 4n+1, W2 is a weight of the row having the row address 4n+2, andW3 is a weight of the row having the row address 4n+3. Here, n is anatural number which includes 0 (that is, n=0, 1, 2, 3, . . . ).

In the present example, the main controller 40 sets W0=1, W1=0, W2=0,and W3=0. Then, the vertical scanning circuit 22 performs additionreadout with the row addresses 4n to 4n+3 as a group on the basis of theset weights W0 to W3. In a case of performing addition readout, thevertical scanning circuit 22 gives a selection signal to the row havinga weight of “1” to turn on the transistor 28, and does not give theselection signal to the row having a weight of “0” to turn off thetransistor 28. Thereby, the pixel signal S is read out only from the rowhaving the row address 4n among the row addresses 4n to 4n+3. Therefore,in the present example, the pixel signal S is output to the signal line23A every four rows in the order of row addresses 0, 4, 8, . . . .

By changing the weights W0 to W3, the main controller 40 makes itpossible to execute one mode among the four types of addition readoutmodes. FIG. 8 shows the weights W0 to W3 respectively corresponding to afirst addition readout mode M1, a second addition readout mode M2, athird addition readout mode M3, and a fourth addition readout mode M4.The first addition readout mode M1 corresponds to the readout methodshown in FIG. 7 , and the readout row address from which the pixelsignal S is read out is “4n”.

The second addition readout mode M2 is executed by setting the weight W1to “1” and the other weights W0, W2, W3 to “0”, and the readout rowaddress is “4n+1”. The third addition readout mode M3 is executed bysetting the weight W2 to “1” and the other weights W0, W1 and W3 to “0”,and the readout row address is “4n+2”. The fourth addition readout modeM4 is executed by setting the weight W3 to “1” and the other weights W0,W1 and W2 to “0”, and the readout row address is “4n+3”.

FIG. 9 shows types of pixels 26 (refer to FIG. 6 ) which are included inthe pixel region 21. Reference numerals R, G, and B in FIG. 9 representcolors of the color filters provided in the pixels 26. The pixel 26provided with these color filters is a pixel used for imaging forgenerating an image, and will be referred to as an imaging pixel Nbelow.

The color array of the color filters shown in FIG. 9 is a so-calledBayer array. The Bayer array is a color array in which the G (green)color filter is disposed on the diagonal two pixels of the 2×2 fourpixels and the R (red) and B (blue) color filters are disposed on theother two pixels. The color array of the color filter is not limited tothe Bayer array, and may be another color array.

Further, the reference numeral F in FIG. 9 indicates a phase differencepixel. The phase difference pixel F is not provided with a color filter.As will be described in detail later, the phase difference pixel Freceives one of the luminous fluxes divided in the X direction about theprincipal ray as a center.

The phase difference pixels F are disposed in the pixel region 21 byreplacing a part of the imaging pixels N in the Bayer array. Forexample, the phase difference pixels F are arranged every three pixels(that is, every two pixels) in the X direction. Further, the pluralityof phase difference pixels F are divided into a first phase differencepixel group F1 and a second phase difference pixel group F2. The firstphase difference pixel group F1 is constituted of the phase differencepixels F each of which receives one of the luminous fluxes divided inthe X direction about the principal ray as a center. The second phasedifference pixel group F2 is constituted of the phase difference pixelsF each of which receives the other of the luminous flux divided in the Xdirection about the principal ray as a center.

Further, the first phase difference pixel group F1 and the second phasedifference pixel group F2 are divided into a plurality of types of phasedifference pixels F having different light receiving characteristics inaccordance with the optical characteristics of the imaging lens 12. InFIG. 9 , there are provided the A pixel line LA in which the phasedifference pixels F corresponding to the first optical characteristicare arranged, the B pixel line LB in which the phase difference pixels Fcorresponding to the second optical characteristic are arranged, and theC pixel line LC in which the phase difference pixels F corresponding tothe third optical characteristic are arranged. In the present example,the A pixel line LA, the B pixel line LB, and the C pixel line LC aredisposed adjacent to each other in the Y direction in this order.

For example, the A pixel line LA is disposed in the row of the rowaddress 4n, the B pixel line LB is disposed in the row of the rowaddress 4n+1, and the C pixel line LC is disposed in the row of the rowaddress 4n+2. Further, in the present example, a plurality of the Apixel line LA, the B pixel line LB, and the C pixel line LC areprovided. FIG. 9 shows two sets of the A pixel line LA, the B pixel lineLB, and the C pixel line LC provided at positions separated by m rows inthe Y direction.

The A pixel line LA, the B pixel line LB, and the C pixel line LC areselectively read out by the above-mentioned addition readout mode (referto FIG. 9 ). Specifically, the A pixel line LA is read out by the firstaddition readout mode M1. The B pixel line LB is read out by the secondaddition readout mode M2. The C pixel line LC is read out by the thirdaddition readout mode M3. That is, by selecting the addition readoutmode, it is possible to read out a pixel line including the phasedifference pixels F corresponding to the optical characteristics of theimaging lens 12.

FIG. 10 shows a configuration of the imaging pixel N. The imaging pixelN includes a photoelectric conversion element 27, a color filter CF, anda microlens ML. The color filter CF is disposed between thephotoelectric conversion element 27 and the microlens ML. The colorfilter CF is a filter that transmits light of any of the colors R, G,and B.

The microlens ML collects the luminous flux incident from the exit pupilEP on the photoelectric conversion element 27 through the color filterCF. The microlens ML is disposed at a position more shifted from thecenter of the photoelectric conversion element 27 as the image height His larger. Specifically, the microlens ML, which is located on one side(hereinafter referred to as the first side) in the X direction withrespect to the position of H=0 as a reference, is located at a positionshifted from the center of the photoelectric conversion element 27 tothe other side (hereinafter referred to as the second side) in the Xdirection. On the contrary, the microlens ML, which is located on thesecond side in the X direction with respect to the position of H=0 as areference, is disposed at a position shifted from the center of thephotoelectric conversion element 27 to the first side.

The principal ray angle θ, which is an incidence angle of the principalray PR of the luminous flux incident from the exit pupil EP, increasesas the image height H increases. Therefore, the principal ray PR can beincident on approximately the center of the photoelectric conversionelement 27 by shifting the microlens ML as described above. Similarly,in the Y direction, the microlens ML is disposed at a position moreshifted from the center of the photoelectric conversion element 27 asthe image height H is larger. By shifting the microlens ML in such amanner, it is possible to improve a decrease in light amount received inthe peripheral region of the pixel region 21 (refer to FIG. 6 ).

FIG. 11 shows configurations of the phase difference pixels F.Specifically, FIG. 11 shows the configurations of the phase differencepixels F which are included in the first phase difference pixel group F1and the second phase difference pixel group F2 in the central regionlocated in the center with respect to the X direction of the pixelregion 21.

The phase difference pixel F includes the photoelectric conversionelement 27, a light blocking layer SF, and the microlens ML. Themicrolens ML is disposed at the same position as the imaging pixel N.That is, the microlens ML is disposed at a position more shifted fromthe center of the photoelectric conversion element 27 as the imageheight H is larger. The phase difference pixel F shown in FIG. 11 islocated in the central region of the pixel region 21 (that is, the imageheight H is substantially 0). Therefore, the amount of shift of themicrolens ML with respect to the center of the photoelectric conversionelement 27 is substantially 0.

The light blocking layer SF is formed of a metal film or the like, andis disposed between the photoelectric conversion element 27 and themicrolens ML. The light blocking layer SF blocks a part of the luminousflux LF incident on the photoelectric conversion element 27 through themicrolens ML.

The principal ray angle θ is substantially 0 in the central portion ofthe pixel region 21. Therefore, the phase difference pixels F which areincluded in the first phase difference pixel group F1 and the phasedifference pixels F which are included in the second phase differencepixel group F2 have structures symmetrical with respect to the Xdirection.

In the phase difference pixels F which are included in the first phasedifference pixel group F1, the light blocking layer SF blocks the firstside from the center of the photoelectric conversion element 27 as areference. That is, in the phase difference pixels F which are includedin the first phase difference pixel group F1, the light blocking layerSF causes the luminous flux from the first side exit pupil EP1 to beincident on the photoelectric conversion element 27, and blocks theluminous flux from the second side exit pupil EP2.

In the phase difference pixels F which are included in the second phasedifference pixel group F2, the light blocking layer SF blocks the secondside from the center of the photoelectric conversion element 27 as areference. That is, in the phase difference pixels F which are includedin the second phase difference pixel group F2, the light blocking layerSF causes the luminous flux from the second side exit pupil EP2 to beincident on the photoelectric conversion element 27, and blocks theluminous flux from the first side exit pupil EP1.

FIG. 12 shows the types of phase difference pixels F which are includedin each region of the pixel region 21. First, in the central regionlocated in the center of the pixel region 21 in the X direction, thefirst phase difference pixel group F1 includes the first A pixel 1AC,the first B pixel 1BC, and the first C pixel 1CC, and the second phasedifference pixel group F2 includes a second A pixel 2AC, a second Bpixel 2BC, and a second C pixel 2CC. The first A pixel 1AC and thesecond A pixel 2AC are disposed on the A pixel line LA. The first Bpixel 1BC and the second B pixel 2BC are disposed on the B pixel lineLB. The first C pixel 1CC and the second C pixel 2CC are disposed on theC pixel line LC.

In the first side region located on the first side in the X direction ofthe pixel region 21, the first phase difference pixel group F1 includesthe first A pixel 1AL, the first B pixel 1BL, and the first C pixel 1CL,and the second phase difference pixel group F2 includes a second A pixel2AL, a second B pixel 2BL, and a second C pixel 2CL. The first A pixel1AL and the second A pixel 2AL are disposed on the A pixel line LA. Thefirst B pixel 1BL and the second B pixel 2BL are disposed on the B pixelline LB. The first C pixel 1CL and the second C pixel 2CL are disposedon the C pixel line LC.

In the second side region located on the second side in the X directionof the pixel region 21, the first phase difference pixel group F1includes the first A pixel 1AR, the first B pixel 1BR, and the first Cpixel 1CR, and the second phase difference pixel group F2 includes asecond A pixel 2AR, a second B pixel 2BR, and a second C pixel 2CR. Thefirst A pixel 1AR and the second A pixel 2AR are disposed on the A pixelline LA. The first B pixel 1BR and the second B pixel 2BR are disposedon the B pixel line LB. The first C pixel 1CR and the second C pixel 2CRare disposed on the C pixel line LC.

For example, the first side region and the second side region areperipheral regions located around the pixel region 21. The first sideregion and the second side region are provided at positions symmetricalwith respect to the central region in the X direction. For example, thefirst side region and the second side region are provided at positionswhere the image height H is, for example, “1”.

FIG. 13 shows a configuration of the phase difference pixels F which areincluded in the A pixel line LA. In the following description, the areawhere the photoelectric conversion element 27 is blocked by the lightblocking layer SF is referred to as a light blocking area.

The A pixel line LA includes phase difference pixels F corresponding tothe first optical characteristic. The first optical characteristic has afeature that the principal ray angle (hereinafter, referred to asperipheral principal ray angle) in the peripheral region of the pixelregion 21 is 0. That is, in the first optical characteristic, theprincipal ray angle θ does not depend on the image height H, and all theprincipal rays PR are parallel to the optical axis OP. The peripheralprincipal ray angle is the principal ray angle in the first side regionand the second side region, and is, for example, the principal ray anglecorresponding to H=1. Hereinafter, the peripheral principal ray angle ofthe first optical characteristic is referred to as the first peripheralprincipal ray angle θ1.

The first A pixel 1AC and the second A pixel 2AC which are included inthe central region have the same configurations as the pair of phasedifference pixels F shown in FIG. 11 . The first A pixel 1AC and thesecond A pixel 2AC have structures symmetrical with respect to the Xdirection. Therefore, the light blocking area S1AC of the first A pixel1AC is equal to the light blocking area S2AC of the second A pixel 2AC.

In the first A pixel 1AL and the second A pixel 2AL which are includedin the first side region, in the same manner as the above-mentionedimaging pixel N, the microlens ML is disposed in a position which isshifted from the center of the photoelectric conversion element 27toward the central region (second side). θ1=0 in the first opticalcharacteristic. Therefore, the principal ray PR is incident at aposition shifted from the center of the photoelectric conversion element27 by a distance corresponding to the amount of shift of the microlensML.

In the first A pixel 1AL, the light blocking layer SF is disposed on thefirst side from the incident position of the principal ray PR of thephotoelectric conversion element 27 so as to block the luminous fluxfrom the exit pupil EP2. In the second A pixel 2AL, the light blockinglayer SF is disposed on the second side from the incident position ofthe principal ray PR of the photoelectric conversion element 27 so as toblock the luminous flux from the exit pupil EP1.

Therefore, the light blocking area S1AL of the first A pixel 1AL islarger than the light blocking area S1AC of the first A pixel 1AC whichis included in the central region. On the other hand, the light blockingarea S2AL of the second A pixel 2AL is smaller than the light blockingarea S2AC of the second A pixel 2AC which is included in the centralregion.

The first A pixel 1AR which is included in the second side region has astructure symmetrical with respect to the second A pixel 2AL which isincluded in the first side region in the X direction. The second A pixel2AR which is included in the second side region has a structuresymmetrical with respect to the first A pixel 1AL which is included inthe first side region in the X direction. Therefore, the light blockingarea S1AR of the first A pixel 1AR is smaller than the light blockingarea S1AC of the first A pixel 1AC which is included in the centralregion. On the other hand, the light blocking area S2AR of the second Apixel 2AR is larger than the light blocking area S2AC of the second Apixel 2AC which is included in the central region.

FIG. 14 shows a configuration of the phase difference pixels F which areincluded in the B pixel line LB. The B pixel line LB includes phasedifference pixels F corresponding to the second optical characteristic.The second optical characteristic has a feature that the peripheralprincipal ray angle is larger than 0. Hereinafter, the peripheralprincipal ray angle of the second optical characteristic is referred toas a second peripheral principal ray angle θ2.

The first B pixel 1BC and the second B pixel 2BC which are included inthe central region have the same configurations as the first A pixel 1ACand the second A pixel 2AC which are included in the central region ofthe A pixel line LA. The first B pixel 1BC and the second B pixel 2BChave structures symmetrical with respect to the X direction. Therefore,the light blocking area S1BC of the first B pixel 1BC is equal to thelight blocking area S2BC of the second B pixel 2BC.

In the first B pixel 1BL and the second B pixel 2BL which are includedin the first side region, the microlens ML is disposed at a positionshifted from the center of the photoelectric conversion element 27toward the central region (second side). In the second opticalcharacteristic, in the first side region, the principal ray PR isincident on substantially the center of the photoelectric conversionelement 27.

In the first B pixel 1BL, the light blocking layer SF is disposed on thefirst side from the incident position of the principal ray PR of thephotoelectric conversion element 27 so as to block the luminous fluxfrom the exit pupil EP2. In the second B pixel 2BL, the light blockinglayer SF is disposed on the second side from the incident position ofthe principal ray PR of the photoelectric conversion element 27 so as toblock the luminous flux from the exit pupil EP1.

Therefore, the light blocking area S1BL of the first B pixel 1BL isequal to the light blocking area S1BC of the first B pixel 1BC which isincluded in the central region. Further, the light blocking area S2BL ofthe second B pixel 2BL is equal to the light blocking area S2BC of thesecond B pixel 2BC which is included in the central region.

The first B pixel 1BR which is included in the second side region has astructure symmetrical with respect to the second B pixel 2BL which isincluded in the first side region in the X direction. The second B pixel2BR which is included in the second side region has a structuresymmetrical with respect to the first B pixel 1BL which is included inthe first side region in the X direction. Therefore, the light blockingarea S1BR of the first B pixel 1BR is equal to the light blocking areaS1BC of the first B pixel 1BC which is included in the central region.Further, the light blocking area S2BR of the second B pixel 2BR is equalto the light blocking area S2BC of the second B pixel 2BC which isincluded in the central region.

FIG. 15 shows a configuration of the phase difference pixels F which areincluded in the C pixel line LC. The C pixel line LC includes phasedifference pixels F corresponding to the third optical characteristic.The third optical characteristic has a feature that the peripheralprincipal ray angle is larger than that of the second opticalcharacteristic. Hereinafter, the peripheral principal ray angle of thethird optical characteristic is referred to as a third peripheralprincipal ray angle θ3.

The first C pixel 1CC and the second C pixel 2CC which are included inthe central region have the same configurations as the first B pixel 1BCand the second B pixel 2BC which are included in the central region ofthe B pixel line LB. The first C pixel 1CC and the second C pixel 2CChave structures symmetrical with respect to the X direction. Therefore,the light blocking area S1CC of the first C pixel 1CC is equal to thelight blocking area S2CC of the second C pixel 2CC.

In the first C pixel 1CL and the second C pixel 2CL which are includedin the first side region, the microlens ML is disposed at a positionshifted from the center of the photoelectric conversion element 27toward the central region (second side). In the third opticalcharacteristic, θ3>θ2. Therefore, the principal ray PR is incident onthe first side of the center of the photoelectric conversion element 27in the first side region.

In the first C pixel 1CL, the light blocking layer SF is disposed on thefirst side from the incident position of the principal ray PR of thephotoelectric conversion element 27 so as to block the luminous fluxfrom the exit pupil EP2. In the second C pixel 2CL, the light blockinglayer SF is disposed on the second side from the incident position ofthe principal ray PR of the photoelectric conversion element 27 so as toblock the luminous flux from the exit pupil EP1.

Therefore, the light blocking area S1CL of the first C pixel 1CL issmaller than the light blocking area S1CC of the first C pixel 1CC whichis included in the central region. On the other hand, the light blockingarea S2CL of the second C pixel 2CL is larger than the light blockingarea S2CC of the second C pixel 2CC which is included in the centralregion.

The first C pixel 1CR which is included in the second side region has astructure symmetrical with respect to the second C pixel 2CL which isincluded in the first side region in the X direction. The second C pixel2CR which is included in the second side region has a structuresymmetrical with respect to the first C pixel 1CL which is included inthe first side region in the X direction. Therefore, the light blockingarea S1CR of the first C pixel 1CR is larger than the light blockingarea S1CC of the first C pixel 1CC which is included in the centralregion. Further, the light blocking area S2CR of the second C pixel 2CRis smaller than the light blocking area S2CC of the second C pixel 2CCwhich is included in the central region.

From the above relationship, in a case where the light blocking areasare compared, a relationship of “S1AL>S1AC>S1AR” and “S2AL<S2AC<S2AR”can be obtained for the A pixel line LA. For the B pixel line LB, arelationship of “S1BL=S1BC=S1BR” and “S2BL=S2BC=S2BR” can be obtained.Regarding the C pixel line LC, a relationship of “S1CL<S1CC<S1CR” and“S2CL>S2CC>S2CR” can be obtained.

Further, for the first side region, a relationship of “S1AL>S1BL>S1CL”and “S2AL<S2BL<S2CL” can be obtained. For the central region, arelationship of “SLAC=S1BC=S1CC” and “S2AC=S2BC=S2CC” can be obtained.For the second side region, a relationship of “S1AR<S1BR<S1CR” and“S2AR>S2BR>S2CR” can be obtained.

FIG. 16 shows an overall configuration of the phase difference pixels Fwhich are included in the pixel region 21. As shown in FIG. 16 , in thepixel region 21, a plurality of sets of A pixel line LA, B pixel lineLB, and C pixel line LC are provided in the Y direction. The pixelregion 21 may be provided with at least one set of the A pixel line LA,the B pixel line LB, or the C pixel line LC.

Further, in the above description, the configuration of the phasedifference pixels F provided in the central region, the first sideregion, and the second side region have been given. However, the samephase difference pixels F are provided along each pixel line between thecentral region and the first side region and between the central regionand the second side region. The light blocking layer SF is formed in thephase difference pixels F so as to receive the luminous flux from theexit pupil EP1 or the exit pupil EP2 in accordance with the opticalcharacteristics corresponding to the pixel lines.

The light blocking area of the plurality of first A pixels arranged onthe A pixel line LA is smaller at a position closer to the second sidefrom the first side. The light blocking areas of the plurality of firstA pixels arranged on the A pixel line LA do not have to be alldifferent, and the first A pixels having the same light blocking areamay be partially arranged.

The light blocking area of the plurality of second A pixels arranged onthe A pixel line LA is larger at a position closer to the second sidethan the first side. The light blocking areas of the plurality of secondA pixels arranged on the A pixel line LA do not have to be alldifferent, and the second A pixels having the same light blocking areamay be partially arranged.

The light blocking areas of the plurality of first B pixels arranged onthe B pixel line LB are all equal. Similarly, the light blocking areasof the plurality of second B pixels arranged on the B pixel line LB areall equal.

The light blocking area of the plurality of first C pixels arranged onthe C pixel line LC is larger at a position closer to the second sidethan the first side. The light blocking areas of the plurality of firstC pixels arranged on the C pixel line LC do not have to be different,and the first C pixels having the same light blocking area may bepartially arranged.

The light blocking area of the plurality of second C pixels arranged onthe C pixel line LC is smaller at a position closer to the second sidefrom the first side. The light blocking areas of the plurality of secondC pixels arranged on the C pixel line LC do not have to be alldifferent, and the second C pixels having the same light blocking areamay be partially arranged.

Next, an operation of the imaging apparatus 10 will be described. FIG.17 is a flowchart showing an example of the flow of processing executedby the main controller 40.

First, in step S10, the main controller 40 acquires lens information 35A(refer to FIG. 4 ) from the imaging lens 12 attached to the body 11. Forexample, the main controller 40 acquires lens information 35A in a casewhere the power switch is turned on while the imaging lens 12 isattached to the body 11. The lens information 35A includes principal rayangle information as optical characteristics of the imaging lens 12.

In step S11, in a case where the operation mode is selected by the dial13, the main controller 40 determines whether or not the selectedoperation mode is the motion picture capturing mode. In a case where theselected operation mode is the motion picture capturing mode (step S11:YES), the main controller 40 advances the processing to step S12. In acase where the selected operation mode is not the motion picturecapturing mode, that is, the still image capturing mode (step S11: NO),the main controller 40 advances the processing to step S13.

In step S12, the main controller 40 selects the addition readout mode(refer to FIG. 8 ) on the basis of the lens information 35A acquired instep S10. The selection of the addition readout mode corresponds to thedetermination of the weights W1 to W3 for the plurality of pixel signalsS for the addition readout.

Specifically, as shown in FIG. 18 , the main controller 40 acquires theperipheral principal ray angle Op (for example, the principal ray angleθ corresponding to H=1) by referring to the lens information 35A. Themain controller 40 selects the addition readout mode corresponding tothe pixel line corresponding to the peripheral principal ray angleclosest to the peripheral principal ray angle Op acquired from the lensinformation 35A among the first peripheral principal ray angle θ1, thesecond peripheral principal ray angle θ2, and the third peripheralprincipal ray angle θ3. For example, the main controller 40 selects thesecond addition readout mode M2 corresponding to the B pixel line LB ina case where the peripheral principal ray angle Op included in the lensinformation 35A is closest to the second peripheral principal ray angleθ2. The selection of the second addition readout mode M2 is performed bysetting W1=1, W0=W2=W3=0.

In a case where the autofocus mode is selected by the instruction key16, the main controller 40 selects any one of the first addition readoutmode M1, the second addition readout mode M2, and the third additionreadout mode M3. On the other hand, in a case where the manual focusmode is selected by the instruction key 16, the main controller 40selects the fourth addition readout mode M4.

Returning to FIG. 17 , in step S13, the main controller 40 selects asequential readout mode in which the pixel signal S is read out by asequential readout method.

In the next step S14, the main controller 40 determines whether or notthe imaging start instruction has been given by operating the releasebutton 14. In a case where the imaging start instruction is given (stepS14: YES), the main controller 40 advances the processing to step S15.

In step S15, the main controller 40 causes the imaging sensor 20 toperform an imaging operation on the basis of the mode selected in stepS12 or step S13. In a case where the motion picture capturing mode isselected, the main controller 40 controls readout of the pixel signal Sfrom the pixel region 21 on the basis of the addition readout modeselected in step S12. As a result, the pixel signal S is sequentiallyread out from the pixel region 21 from the row in which the weight isset to “1”, that is, the row corresponding to the pixel line selected instep S12.

For example, in a case where the second addition readout mode M2corresponding to the B pixel line LB is selected in step S12, the pixelsignal S is selectively read out from the row of the row address 4n+1including the B pixel line LB. The pixel signal S which is read out fromthe imaging pixel N and the pixel signal S which is read out from thephase difference pixel F are input to the image processing unit 41 as animaging signal.

In a case where the fourth addition readout mode M4 is selected in stepS12, the pixel signal S is read out from the row at the row address 4n+3that does not include the phase difference pixel F. Therefore, only thepixel signal S which is read out from the imaging pixel N is input tothe image processing unit 41.

In step S16, the image processing unit 41 performs image processing. Theimage processing unit 41 generates image data representing a subjectimage by performing demosaic processing or the like on the basis of thepixel signal S which is read out from the imaging pixel N. The imageprocessing unit 41 is unable to obtain a pixel signal for imaging fromthe phase difference pixel F. Therefore, the image processing unit 41calculates pixel values corresponding to the positions of the phasedifference pixels F in the image data by performing complementaryprocessing on the basis of the pixel values in the vicinity thereof.

Further, in step S16, the main controller 40 performs focusing controlby the phase difference method on the basis of the pixel signal S whichis read out from the phase difference pixel F. Specifically, the maincontroller 40 adjusts the position of the focus lens 31 so as to reducethe phase differences between images of the pixel signals S obtainedfrom the phase difference pixels F which are included in the first phasedifference pixel group F1 and the pixel signals S obtained from thephase difference pixels F which are included in the second phasedifference pixel group F2. For example, in a case where the B pixel lineLB is selected, focusing control is performed on the basis of the phasedifferences between the pixel signals S of the first B pixel 1BL, thefirst B pixel 1BC, and the first B pixel 1BR and the pixel signals S ofthe second B pixel 2BL, the second B pixel 2BC, and the second B pixel2B R.

In the motion picture capturing mode, the main controller 40 repeatedlyperforms the processing of steps S15 and S16, and ends the imagingoperation in a case where the imaging end instruction is given. Thereby,the image processing unit 41 generates motion picture data in which thesignal amount of the imaging signal is reduced by ¼ times.

Further, in step S15, in a case where the still image capturing mode isselected, the readout of the pixel signal S from the pixel region 21 iscontrolled on the basis of the sequential readout mode. As a result, thepixel signal S is read out from all the pixels in the pixel region 21and input to the image processing unit 41. In such a case, in step S16,the image processing unit 41 generates still image data. In the stillimage capturing mode, the live view image display and focusing controlmay be performed by reading out the pixel signal S in the additionreadout mode similar to the motion picture capturing mode during thepreparatory operation performed in accordance with the half-pressing ofthe release button 14.

As described above, according to the imaging apparatus 10 of the firstembodiment, focusing control can be performed by using pixel signals ofappropriate phase difference pixels according to the opticalcharacteristics of the imaging lens.

Second Embodiment

Next, a second embodiment of the present disclosure will be described.In the second embodiment, the main controller 40 makes it possible toperform readout in the fifth addition readout mode M5 and the sixthaddition readout mode M6 in addition to the addition readout modedescribed in the first embodiment. Other configurations of the imagingapparatus of the second embodiment are the same as the configurations ofthe imaging apparatus 10 of the first embodiment.

FIG. 19 is a diagram showing a fifth addition readout mode M5. The fifthaddition readout mode M5 is a so-called two-pixel addition readoutmethod in which the gate lines 22A are set by two rows and two pixelsignals S are added and read out in order. The main controller 40 makesit possible to set weights for the A pixel line LA, the B pixel line LB,and the C pixel line LC. The main controller 40 performs additionreadout on the basis of the weight, as in the first embodiment.

The weight for the A pixel line LA is Wa, the weight for the B pixelline LB is Wb, and the weight for the C pixel line LC is Wc. In thefifth addition readout mode M5, the main controller 40 performs additionreadout with the A pixel line LA and the B pixel line LB as a set in acase where Wa=1, Wb=1, and Wc=0. In such a case, the pixel signal S fromthe A pixel line LA and the pixel signal S from the B pixel line LB areadded and averaged at a ratio of 1:1.

The main controller 40 selects the fifth addition readout mode M5 in acase where the value of the peripheral principal ray angle θp includedin the lens information 35A is between the first peripheral principalray angle θ1 and the second peripheral principal ray angle θ2. In thefifth addition readout mode M5, for example, by adding the pixel signalS of the first A pixel 1AL and the pixel signal S of the first B pixel1BL, it is possible to obtain the pixel signal corresponding to thefourth peripheral principal ray angle θ4 represented by Expression (1).

θ4=(θ1+θ2)/2  (1)

As described above, by using the fifth addition readout mode M5, it ispossible to appropriately perform focusing control even in a case wherethe imaging lens 12 having the peripheral principal ray angle θp betweenthe first peripheral principal ray angle θ1 and the second peripheralprincipal ray angle θ2 is attached to the body 11.

FIG. 20 is a diagram showing a sixth addition readout mode M6. The sixthaddition readout mode M6 is a two-pixel addition readout methodsimilarly to the fifth addition readout mode M5, but the set row isdifferent from that of the fifth addition readout mode M5.

In the sixth addition readout mode M6, the main controller 40 performsaddition readout with the B pixel line LB and the C pixel line LC as aset in a case where Wa=0, Wb=1, and We=1. In such a case, the pixelsignal S from the B pixel line LB and the pixel signal S from the Cpixel line LC are added and averaged at a ratio of 1:1.

The main controller 40 selects the sixth addition readout mode M6 in acase where the value of the peripheral principal ray angle θp includedin the lens information 35A is between the second peripheral principalray angle θ2 and the third peripheral principal ray angle θ3. In thesixth addition readout mode M6, for example, by adding the pixel signalS of the first B pixel 1BL and the pixel signal S of the first C pixel1CL, it is possible to obtain the pixel signal corresponding to thefifth peripheral principal ray angle θ5 represented by Expression (2).

θ5=(θ2+θ3)/2  (2)

As described above, by using the sixth addition readout mode M6, it ispossible to appropriately perform focusing control even in a case wherethe imaging lens 12 having the peripheral principal ray angle θp betweenthe second peripheral principal ray angle θ2 and the third peripheralprincipal ray angle θ3 is attached to the body 11.

In the fifth addition readout mode M5 and the sixth addition readoutmode M6, the two pixel signals are added at a ratio of 1:1, but can alsobe added at another ratio such as 1:2. As described above, an imagingapparatus capable of performing pixel addition at a ratio other than 1:1is known, for example, in JP2015-128215A.

For example, by setting Wa=1 and Wb=2 in the fifth addition readout modeM5, it is possible to acquire the pixel signal corresponding to thesixth peripheral principal ray angle θ6 represented by Expression (3),from the first A pixel 1AL and the first B pixel 1BL.

θ6=(θ1+2×θ2)/3  (3)

In such a manner, by changing the ratio of the weights Wa, Wb, and We inthe fifth addition readout mode M5 and the sixth addition readout modeM6, it is possible to perform focusing control appropriatelycorresponding to various peripheral principal ray angles Op.

In each of the above-mentioned embodiments, three types of pixel lines,the A pixel line LA, the B pixel line LB, and the C pixel line LC, areprovided as the pixel lines including the phase difference pixels F, butfour or more types of the pixel lines may be provided. Further, at leasttwo types of pixel lines including the phase difference pixels F may beprovided.

Further, in each of the above-mentioned embodiments, the phasedifference pixels F which are included in the first phase differencepixel group F1 and the phase difference pixels F which are included inthe second phase difference pixel group F2 are disposed with two imagingpixels interposed therebetween N in the X direction, but both may beadjacent to each other. Further, it is preferable that the phasedifference pixels F which are included in the first phase differencepixel group F1 and the phase difference pixels F which are included inthe second phase difference pixel group F2 are disposed with three orless imaging pixels N interposed therebetween.

Further, in each of the above-mentioned embodiments, the phasedifference pixel F corresponding to the first optical characteristic,the phase difference pixel F corresponding to the second opticalcharacteristic, and the phase difference pixel F corresponding to thethird optical characteristic are respectively disposed to be dividedinto the A pixel line LA, the B pixel line LB, and the C pixel line LC.The phase difference pixels F corresponding to these plurality ofoptical characteristics may be mixedly disposed in one pixel line.

Further, in each of the above-mentioned embodiments, the pixel linesincluding the phase difference pixels F extend in the X direction, butmay be configured to extend in the Y direction. In such a case, theabove-mentioned addition readout may be performed along the X directioninstead of the Y direction. As described above, a configuration forperforming addition readout in the X direction (horizontal direction) isknown, for example, in JP2015-128215A.

Further, in each of the above-mentioned embodiments, addition isperformed on two adjacent pixels in the addition readout mode, butaddition readout may be performed on two pixels disposed with at leastone pixel interposed in the X direction or the Y direction. As describedabove, a configuration in which addition readout is performed for twoseparated pixels is known, for example, in JP2015-128215A.

Further, in each of the above-mentioned embodiments, the main controller40 selects the addition readout mode on the basis of the peripheralprincipal ray angle which is the principal ray angle in the peripheralregion of the pixel region 21, but may select the addition readout modeon the basis of the angle of the principal ray incident on a regionother than the peripheral region of the pixel region 21.

Third Embodiment

Next, a third embodiment of the present disclosure will be described. Inthe first embodiment, the main controller 40 selects the additionreadout mode on the basis of the principal ray angle informationincluded in the lens information 35A acquired from the imaging lens 12.In the third embodiment, the main controller 40 selects the additionreadout mode on the basis of the focal length of the imaging lens 12.Other configurations of the imaging apparatus of the third embodimentare the same as the configurations of the imaging apparatus 10 of thefirst embodiment.

In the third embodiment, the lens information 35A stored in the memory35 of the imaging lens 12 includes information about the focal lengthpeculiar to the imaging lens 12. As shown in FIG. 21 , for example, themain controller 40 stores a table TB in which the focal length and theperipheral principal ray angle θp are associated with each other.Generally, the peripheral principal ray angle θp approaches 0 as thefocal length becomes longer. The main controller 40 may store arelationship between the focal length and the peripheral principal rayangle θp through a function instead of the table TB.

After acquiring the lens information 35A from the imaging lens 12attached to the body 11, the main controller 40 acquires the peripheralprincipal ray angle θp corresponding to the focal length included in thelens information 35A by referring to the table TB. Then, the maincontroller 40 selects the addition readout mode on the basis of theacquired peripheral principal ray angle θp by the same method as in thefirst embodiment (refer to FIG. 18 ).

According to the present embodiment, even in a case where the imaginglens 12 whose principal ray information is not included in the lensinformation 35A is attached to the body 11, it is possible to performfocusing control using the pixel signals of appropriate phase differencepixels.

Fourth Embodiment

Next, a fourth embodiment of the present disclosure will be described.In each of the above-mentioned embodiments, the imaging lens 12 is asingle focus lens, but in the fourth embodiment, the imaging lens 12 isa zoom lens whose focal length can be changed. Further, the imagingapparatus of the fourth embodiment may be an integrated digital camerain which the imaging lens 12 and the body 11 are inseparably connected.Other configurations of the imaging apparatus of the fourth embodimentare the same as the configurations of the imaging apparatus 10 of thefirst embodiment.

In the imaging apparatus of the fourth embodiment, the focal length canbe changed (that is, the zoom magnification can be changed) by operatingthe zoom ring (not shown) provided on the imaging lens 12 or theinstruction key 16. In the fourth embodiment, as in the thirdembodiment, the main controller 40 maintains the relationship betweenthe focal length and the peripheral principal ray angle θp. The maincontroller 40 selects the addition readout mode by the same method as inthe third embodiment in accordance with the change of the focal lengthby the zoom operation.

In a case where the zoom operation is performed during the motionpicture capturing and change processing of the addition readout mode isconstantly performed in conjunction with the zoom operation, a motionpicture that gives the user a sense of discomfort may be generated.Therefore, it is preferable to select the addition readout mode (thatis, change the weight) in a case where the focal length is changed bythe zoom operation and the change of the focal length is stopped.

For example, the main controller 40 performs weight change processingaccording to the procedure shown in FIG. 22 . First, in step S20, themain controller 40 determines whether or not motion picture capturinghas started. In a case where the main controller 40 determines that themotion picture capturing has started (step S20: YES), the processingadvances to step S21.

In step S21, the main controller 40 determines whether or not the focallength has been changed by the zoom operation. In a case where the maincontroller 40 determines that the focal length has been changed (stepS21: YES), the processing advances to step S22. In step S22, the maincontroller 40 determines whether or not the change of the focal lengthhas stopped. In a case where the main controller 40 determines that thechange of the focal length has stopped (step S22: YES), the processingadvances to step S23. In step S23, the main controller 40 changes theaddition readout mode by selecting a weight according to the focallength at a time point at which the change of the focal length isstopped.

In the next step S24, the main controller 40 determines whether or notthe motion picture capturing has stopped. In a case where the maincontroller 40 determines that the motion picture capturing has notstopped (step S24: NO), the processing returns to step S21. That is, ina case where the motion picture capturing is not stopped, the maincontroller 40 repeatedly executes steps S21 to S24. Then, in a casewhere the main controller 40 determines that the motion picturecapturing has stopped (step S24: YES), the main controller 40 ends thechange processing.

The change processing of the present embodiment is not limited to thetime of motion picture capturing, but can also be performed during thedisplay of the live view image performed in the preparatory stage ofstill image capturing.

Fifth Embodiment

Next, a fifth embodiment of the present disclosure will be described. Inthe fifth embodiment, even in a case where it is difficult to acquirethe lens information 35A (that is, the optical characteristic) from theimaging lens 12, it is possible to select a pixel line including thephase difference pixels F suitable for the optical characteristics ofthe imaging lens 12. Other configurations of the imaging apparatus ofthe fifth embodiment are the same as the configurations of the imagingapparatus 10 of the first embodiment.

In the fifth embodiment, in a case where the optical characteristics areunlikely to be acquired from the imaging lens 12, the main controller 40determines a weight of the addition readout, on the basis of theexposure amount to the phase difference pixels F which are included inthe first phase difference pixel group F1 and the phase differencepixels F which are included in the second phase difference pixel groupF2.

FIG. 23 shows differences in the exposure amount between the first Apixel 1AL and the second A pixel 2AL and between the first B pixel 1BLand the second B pixel 1BL with respect to a certain opticalcharacteristic of the imaging lens 12. FIG. 23 shows the principal rayPR in a case where the imaging lens 12 having the second opticalcharacteristic shown in FIG. 14 is attached to the body 11.

The first A pixel 1AL and the second A pixel 2AL are phase differencepixels F disposed on the A pixel line LA, and correspond to theperipheral principal ray angle θ1 of the first optical characteristic(refer to FIG. 13 ). Therefore, in a case where the principal ray PR ofthe second optical characteristic is incident on the first A pixel 1ALand the second A pixel 2AL, the peripheral principal ray angle θp of theincident light is different from the corresponding peripheral principalray angle θ1. Therefore, there is a difference in both exposure amounts.Here, the exposure amount corresponds to the magnitude of the pixelsignal S.

Specifically, in the first A pixel 1AL, the light blocking layer SFblocks the luminous flux from the exit pupil EP2 and a part of theluminous flux from the exit pupil EP1. Therefore, the exposure amount islower than the appropriate value. On the other hand, in the second Apixel 2AL, the light blocking layer SF blocks only a part of theluminous flux from the exit pupil EP1. Therefore, the light amountbecomes greater than the appropriate value. Therefore, the exposureamount difference Δ occurs between the first A pixel 1AL which is aphase difference pixel F included in the first phase difference pixelgroup F1 and the second A pixel 2AL which is a phase difference pixel Fincluded in the second phase difference pixel group F2.

The first B pixel 1BL and the second B pixel 2BL are phase differencepixels F disposed on the A pixel line LA, and correspond to theperipheral principal ray angle θ2 of the second optical characteristic(refer to FIG. 14 ). Therefore, in a case where the principal ray PR ofthe second optical characteristic is incident on the first A pixel 1ALand the second A pixel 2AL, the peripheral principal ray angle θp of theincident light matches the corresponding peripheral principal ray angleθ1. Therefore, the exposure amount difference Δ is 0. Therefore, theexposure amount difference Δ does not occur between the first B pixel1BL which is a phase difference pixel F included in the first phasedifference pixel group F1 and the second B pixel 2BL which is a phasedifference pixel F included in the second phase difference pixel groupF2.

As described above, the main controller 40 determines the weight of theaddition readout so as to select the pixel line having the smallestexposure amount difference Δ on the basis of the exposure amountdifferences A between the phase difference pixels F which are includedin the first phase difference pixel group F1 and the phase differencepixels F which are included in the second phase difference pixel groupF2.

The main controller 40 performs weight determination processing in theprocedure shown in FIG. 24 , for example. First, in step S30, the maincontroller 40 determines whether or not it is possible to acquire thelens information 35A from the imaging lens 12 in a case where theimaging lens 12 is attached to the body 11. In a case where it ispossible to acquire the lens information 35A (step S30: YES), the maincontroller 40 ends the weight determination processing and determinesthe weight in the procedure shown in the first embodiment.

In a case where the main controller 40 is unable to acquire the lensinformation 35A (step S30: NO), the main controller 40 advances theprocessing to step S31. In step S31, the main controller 40 acquires thepixel signal S from, for example, the phase difference pixels F whichare included in the first phase difference pixel group F1 and the secondphase difference pixel group F2 in the first side region. At this time,it is preferable that the imaging sensor 20 captures an image under auniform light amount.

In the next step S32, the main controller 40 obtains the exposure amountdifferences A between the phase difference pixels F which are includedin the first phase difference pixel group F1 and the phase differencepixels F which are included in the second phase difference pixel groupF2. The main controller 40 calculates, for example, each of an exposureamount difference Δ between the first A pixel 1AL and the second A pixel2AL, an exposure amount difference Δ between the first B pixel 1BL andthe second B pixel 2BL, and an exposure amount difference Δ between thefirst C pixel 1CL and the second C pixel 2CL.

In the next step S33, the main controller 40 determines the weight ofaddition readout so as to select a pixel line including the pair ofphase difference pixels F having the smallest exposure amount differenceΔ among the exposure amount differences A obtained in step S32. Forexample, in a case where the exposure amount difference Δ between thefirst B pixel 1BL and the second B pixel 2BL is the smallest, the weightis determined to be W1=1 and W0=W2=W3=0 so as to select the B pixel lineLB (refer to FIG. 8 ). Thereby, the second addition readout mode M2 isselected.

Thereby, the main controller 40 ends the weight determinationprocessing. After that, in a case where the motion picture capturing isstarted, the main controller 40 reads out the pixel signal S using theaddition readout mode determined in step S33.

In the third embodiment, in a case where the optical characteristics ofthe imaging lens 12 are unlikely to be acquired, the weight isdetermined on the basis of the exposure amount of the phase differencepixel F, but a default weight may be selected. For example, in a casewhere the optical characteristics of the imaging lens 12 are unlikely tobe acquired, the main controller 40 determines the weights of W1=1 andW0=W2=W3=0 so as to select the B pixel line LB including the first Bpixel 1BL and the second B pixel 2BL having the same light blocking area(opening amount) (refer to FIG. 8 ). Thereby, the second additionreadout mode M2 is selected.

The first B pixel 1BL and the second B pixel 2BL have the same lightblocking area, and thus are most suitable in a case where the opticalcharacteristics of the imaging lens 12 are unknown. Thereby, it ispossible to cope with a situation in which the optical characteristicsof the imaging lens 12 are unlikely to be acquired and the imaging fordetermining the weight is unlikely to be performed.

In each of the above-mentioned embodiments, the microlens ML is shiftedfrom the center of the photoelectric conversion element 27 in accordancewith the image height H, but in the technique of the present disclosure,it is not essential to shift the microlens ML.

In each of the above-mentioned embodiments, various processors shownbelow can be used as the hardware structure of the controller using themain controller 40 as an example. In addition to the CPU which is ageneral-purpose processor that functions by executing software(programs), the above-mentioned various processors include PLD such asFPGA which is a processor whose circuit configuration can be changedafter manufacturing, a dedicated electric circuit such as ASIC which isa processor having a circuit configuration specially designed forexecuting specific processing, and the like.

The controller may be constituted of one of the various processors, ormay be constituted of a combination of two or more processors of thesame type or different types (for example, a combination of a pluralityof FPGAs or a combination of a CPU and an FPGA). Further, the pluralityof controllers may be constituted of one processor.

As an example of the plurality of controllers constituted of oneprocessor, first, as represented by computers such as a client and aserver, there is a form in which one processor is constituted of acombination of one or more CPUs and software and this processorfunctions as a plurality of controllers. Secondly, as typified by systemon chip (SOC), there is a form in which a processor that realizes thefunctions of the whole system including a plurality of controllers withone IC chip is used. As described above, the controller can beconfigured by using one or more of the above-mentioned variousprocessors as a hardware-like structure.

Further, as the hardware structure of these various processors, morespecifically, it is possible to use an electric circuit in which circuitelements such as semiconductor elements are combined.

The contents described and illustrated above are detailed descriptionsof the parts relating to the technique of the present disclosure, andare merely examples of the technique of the present disclosure. Forexample, the above description of the configuration, function, effect,and advantage is an example of the configuration, function, effect, andadvantage of a portion relating to the technique of the presentdisclosure. Therefore, it is needless to say that unnecessary parts maybe deleted, new elements may be added, or replacements may be made inthe described contents and illustrated contents shown above withoutdeparting from the technical scope of the present disclosure. Inaddition, in order to avoid complications and facilitate understandingof the parts relating to the technique of the present disclosure, in thedescription contents and the illustrated contents shown above, thedescription about common technical knowledge and the like which requirespecial explanation in order to enable the implementation of thetechnique of the present disclosure is not given.

All documents, patent applications, and technical standards described inthe present specification are incorporated into the presentspecification by reference to the same extent as in a case where theindividual documents, patent applications, and technical standards werespecifically and individually stated to be incorporated by reference.

What is claimed is:
 1. An imaging apparatus comprising: a pixel regionin which a plurality of pixels are arranged and into which light isincident through an imaging lens; and a controller that controls readoutof a pixel signal from the pixel region, wherein in the pixel region,phase difference pixels, each of which includes a photoelectricconversion element, and a light blocking layer, which blocks a part oflight incident on the photoelectric conversion element, are arrangedalong a first direction, in a case where one side in the first directionis set as a first side and the other side is set as a second side, thepixel region includes a first phase difference pixel group including aplurality of the phase difference pixels of which the first side of thephotoelectric conversion element is blocked by the light blocking layerin a first side region of the first side, and a second phase differencepixel group including a plurality of the phase difference pixels ofwhich the second side of the photoelectric conversion element is blockedby the light blocking layer, and the first phase difference pixel groupincludes a first A pixel and a first B pixel in which a light blockingarea of the photoelectric conversion element using the light blockinglayer is smaller than that of the first A pixel, and the controlleracquires the optical characteristics from the imaging lens and performsaddition readout processing in which at least one of a pixel signal ofthe first A pixel or a pixel signal of the first B pixel is weighted inaccordance with the acquired optical characteristics, wherein in a casewhere the optical characteristics are unlikely to be acquired from theimaging lens, the controller performs the addition readout processingwith the weight as a default value.
 2. The imaging apparatus accordingto claim 1, wherein the second phase difference pixel group includes asecond A pixel and a second B pixel in which a light blocking area ofthe photoelectric conversion element using the light blocking layer islarger than that of the second A pixel, and the controller performsaddition readout processing in which either one of a set of the first Apixel and the second A pixel or a set of the first B pixel and thesecond B pixel is weighted in accordance with the acquired opticalcharacteristics.
 3. The imaging apparatus according to claim 1, whereinthe pixel region has an A pixel line that includes the first A pixel andhas a plurality of pixels arranged in the first direction, and a B pixelline that includes the first B pixel and has a plurality of pixelsarranged in the first direction, the A pixel line and the B pixel lineare arranged in a second direction intersecting with the firstdirection, and the controller performs addition readout processing inwhich either one of the A pixel line or the B pixel line is weighted inaccordance with the acquired optical characteristics.
 4. The imagingapparatus according to claim 3, wherein the first phase difference pixelgroup is also included in a central region located at a center of thepixel region with respect to the first direction, in the A pixel line, alight blocking area of the first A pixel which is included in the firstside region is larger than a light blocking area of the first A pixelwhich is included in the central region, and in the B pixel line, alight blocking area of the first B pixel which is included in the firstside region is equal to a light blocking area of the first B pixel whichis included in the central region.
 5. The imaging apparatus according toclaim 4, wherein the light blocking area of a plurality of the first Apixels which are included in the A pixel line is smaller at a positioncloser to the central region than the first side region.
 6. The imagingapparatus according to claim 3, wherein the A pixel line and the B pixelline are adjacent to each other in the second direction.
 7. The imagingapparatus according to claim 3, wherein in the pixel region, the phasedifference pixels which are included in the first phase difference pixelgroup are formed in a second side region on the second side, and in theA pixel line, a light blocking area of the first A pixel which isincluded in the second side region is smaller than a light blocking areaof the first A pixel which is included in the first side region.
 8. Theimaging apparatus according to claim 1, wherein the opticalcharacteristics are an incidence angle of the light with respect to thepixel region, a focal length of the imaging lens, or a zoommagnification of the imaging lens.
 9. The imaging apparatus according toclaim 8, wherein the focal length of the imaging lens can be changed,and the controller changes the weight in a case where the focal lengthis changed and the change is stopped.
 10. The imaging apparatusaccording to claim 1, wherein the pixel region has a gate line thatextends in the first direction and selects the photoelectric conversionelement which reads out the pixel signal, and a signal line that extendsin a second direction intersecting with the first direction and outputsa pixel signal from the photoelectric conversion element.
 11. Theimaging apparatus according to claim 1, wherein the addition readoutprocessing includes thinning-out readout processing in which the weightis set to zero so that a pixel signal having a weight of zero is thinnedout and a pixel signal whose weighting is not zero is read out.